The present invention relates to lubricant compositions and more specifically to lubricant emulsions comprising mineral oil and water that are suitable for use in metalworking operations such as the cold rolling and hot rolling of aluminum and aluminum alloys.
In the rolling of metals such as aluminum and aluminum alloys, it is customary to flood the rolls and the workpiece with a coolant in order to carry away heat generated by the operation. It is also customary to use as a coolant an emulsion comprising water, mineral oil and various additives having load bearing and friction-modifying properties for reducing friction between the rolls and workpiece. In order to perform satisfactorily in industry, the lubricant fluid must meet several important requirements.
Among the requirements for a satisfactory metalworking lubricant are corrosion-inhibiting properties and stability under operating conditions. In addition, the lubricant should not cause deposits on the rolls and workpiece during the rolling operation. Such deposits result from the drying of fluid and they are difficult to remove. Other important requirements include avoidance of excessive foam formation and an emulsion stability sufficient to wet the tool and workpiece.
Lubricant emulsions containing water and mineral oil are known in the prior art. However, there is a continuing need to improve the performance characteristics of such lubricant emulsions.
It is a principal object of the present invention to provide a lubricant emulsion suitable for metal rolling and having a reduced tendency to form deposits on the rolls and workpiece during the rolling operation in which such emulsion is used.
It is a related object of the invention to provide a mineral oil lubricant composition in which an alkoxyalkyl ester comprises the principal film strength additive.
Additional objects and advantages of the invention will be apparent to persons skilled in the art upon reading the following detailed description.